Gun rifling machine



May 4, 1943. w. F. GROENE 'ET AL GUN RIFLING MACHINE Filed Dec. 11, 1941s Sheets-Shet 1 mm I @m 2 H E 1 \r\.\l\\\ V 0 mm E 1 l1? qlllll 1 +0 mmav INVENTORS. WILLIAM F. GROENE HARRT F. STOFFREGEN JR.

May 4, 1943.

W. F. GROENE ETAL GUN RIFL ING MACHINE Filed Dec. 11, 1941 5Sheets-Sheet 2 1 VII rt I .FIIIIIIZ. l

mm w all I;

I I W 2 iidlllfll INVENTORS.

M F. GROENE RT F. STOFFREQEN JR. WM {5 M WILLIA HAR 3 Sheets-Sheet 3INVENTORS. F. GROENE OFFREGEN JR.

WILLIAM RT F. s7

mw w HAR Dec. 11, 1941 w. F. GROENE EI'AL GUN RIFLING- MACHINE lllllllml. ll

I WW;

May 4, 1943.

IIHIIHIII I Illlllllll Ill-l IIP IIIILI Patented May 4, 1943 GUN RIFLINGMACHINE William F. Greene and Harry F. Stofiregen, Jr., Cincinnati,Ohio, assignors to The R. K. Le. Blond Machine. Tool Company,Cincinnati, Ohio, a. corporation of Delaware Application December 11,1941, Serial No. 422,474

4 Claims.

This invention pertains. to gun rifling machines, and is. specificallyrelated to cutting tool supporting and actuating mechanism used' inconjunction with such. machines for cutting the rifling grooves in thebore. of a gun barrel. This invention is related to our co-pendingapplication Serial No. 390,090 filed April 24, 1941. One of the chiefpurposes of this invention is to provide a rifling cutting tool which isof such design as to completely eliminate vibration and chatter in thecutting tool as it is being drawn through the gun barrel to effect thecutting of the rifling grooves.

It is also an object of this invention to design a rifling tool supportwhich avoids the use of flexible or spring mounted tool holder mechanismand which may be adjusted automatically for tool relief movement duringthe return stroke after cutting each rifle groove.

It is also an object to provide a rifling groove cutting tool holdercomprising a solid integral member pivotally mounted on a slidingtubular carrier member operating in the gun bore and in which thecutting tool edge is formed integrally therewith.

And it is a further object to provide, in conjunction with such anarrangement, means for automatically moving said pivotal tool holder andtool in tool relief movement and to proper depth of cut by mechanism inwhich there is no backlash between the tool carrier and the pivotal toolholder mounted thereon at any time during the tool relief movement.

Certain specific improvements in the application of the cutting coolantto the tool holder and tool are also contemplated.

Further features and advantages of this invention will appear from thdetailed description of the drawings in which:

Figure I is a front perspective view of a typical gun rifling machineincorporating the principles of this invention.

Figure II is an enlarged sectional view taken longitudinally of themachine on the line IIII of Figure I11, particularly showing themechanism for advancing the tool in cutting relation to the groove to becut in the gun bore for each additional depth of cut of the tool in thevarious rifling grooves.

Figure III is an axial View of the tool feeding unit of Figure II shownparticularly in the line III-III of Figure II.

Figure IV is a longitudinal section of the feeding carriage slidablymounted on the bed ways.

Figure V is a vertical longitudinal section through the rifling toolmounting mechanismshown in section on the line VV' in Figures VII andVIII.

Figure VI is a horizontal longitudinal section of the gun barrel andrifling tool holder partic--. ularly showing the top view of thepivoting cutting tool holder and its cutting tool point, shown on theline VI-VI of Figures VII and VIII.

Figure VII is an enlarged transverse sectional view through the gunbarrel and rifling tool sup.. porting mechanism shown on the lineVIIIe-VIII of Figures V and- VI.

Figure VIII is a similar transverse enlarged sectional view through therifling tool support, ing mechanism taken atits pivot end joint shown onthe line VIII-VIII of Figures V and VI. 7

Figure IX is an end View of the gun barrel at the completion of therifling operation showing the relationship of the bore to the riflinggrooves in the gun.

Figure X is a diagrammatic view showing the essential elementscomprising the apparatus for operating the novel rifling tool supportingmech-'- anism.

For exemplary purposes this invention is shown applied to a gun riflingmachine comprising a bed I which is carried on'legs 2,3, 4, and 5, andhas appropriate ways 6 and I prepared on its upper surface. On theseways 6 and l is fixed the indexing work carrying head 8 having arotatable work spindle 9 suitably journaled in the housing 8 and havinga work'gripping chuck III for gripping the gun barrel II. The outer endof the gun barrel II is mounted in a. similar fixture having a workgripping chuck I2 carried on a freely rotatable spindle I3 in the outersupporting housing I4 so as to serve as a rotating steady rest forsupporting the outer end of the gun barrel I I.

Slidably mounted on the ways 6 and I of the bed I is the rifling barcarriage I5 and the tool feeding unit I6. The unit I6 is arranged to beclamped directly to th piston rod I! of the feeding and rapid traversingcylinder I8 fixed in the bed I of the machine, by mean of a suitableclamp I9 which may be locked to the rod I! by tightening the nuts 20 onthe bolts 2|, shown best in Figures 11 and III, so that this feedingunit is at all times carried in either direction by the motion of thepiston 22 in the cylinder I8 in actuating its piston rod I! in feedingor rapid traverse movement.

Also the carriage I5 is similarly actuated from the piston rod I! of thecylinder I8 but in delayed motion relative to the feeding unit I6 whenreversal of feed and rapid traverse takes place. This arrangementcomprises a collar 23 fixed to the piston rod II by suitable pin 24 andan adjustable collar 25 appropriately connected by threaded means 26 tothe outer end of the piston rod II, the piston rod II passing throughsuitable supporting bearings 21 and 28 in depending central portions 29of the carriage I5. The collar 23 is arranged to abut against thesurface 36 of the carriage I when effecting the feeding or cuttingdirection of movement of the carriage I5 and upon reversal of the piston22 in cylinder IS the piston rod II then moves in the oppositedirection, to the left in Figure IV, to bring the collar in engagementwith the abutment sur is the rifling bar spindle housing 33 which carries the rifling bar spindle 34 on suitable bearings 35 for freerotation in the housing 33 against axial movement. To this spindle 34 isappropriately connected the spiral grooved rifling bar 36 by means ofsuitable coupling means 31.

This rifling bar 36 has an appropriate spiral groove 38 formed thereinof precisely the lead desired for the rifling grooves 39 to be formed inthe bore 46 of the gun barrel II, Figure IX. This rifling bar 36 isarranged for sliding motion through an appropriate bore 4I formed in thesupport member 42 fixed to the bed I of the machine by suitable screws43 and which carry a plunger screw 44 which is arranged to nicely engagein the groove 38 so that as the bar 36 is moved through the member 42 bymotion of the carriage I5 it will be rotated in proper spiral angularmovement to effect the proper lead in the rifling 3-9 to be formed inthe gun I I.

Referring particularly to Figures II and III the outer end of the spiralgrooved rifiing bar 36 is slidably carried in the bore 45 of the sleeve46 and rotates the sleeve 46 through the medium of the key 46a, FigureIII. A pin 41 is mounted by means of suitable shoes 48 in the sleeve 46and which passes through slotted portion 49 formed in the rifling bar 36so as to permit axial movement of the bar 36 relative to the sleeve 46.The sleeve 46 is journaled against axial movement in the bore 50 of thefeed adjusting sleeve 5| which is arranged for axial sliding motion inthe bore 52 of the feed adjusting unit I6 and is confined from rotationin said bore 52 by means of a suitable key 53 fixed to the unit I6 whichoperates in a keyway 54 formed in the outside diameter portion of thesleeve 5|.

The feed adjusting sleeve 5I may be accurately moved axially in the bore52 of the unit I6 by means of an adjusting nut 55 which is confinedaganist axial movement relative to the unit I6 by means of its flangedportion 56 and the clamp ring 5! fixed to the unit I6 so that while thenut may be rotated it will have no relative axial v motion with respectto the unit I6. This nut 55 has an appropriate threaded connection 58with the sleeve 5I and it may be rotated by means of the pilot handwheel 59 suitably connected to it rotated the sleeve 5I may beaccurately moved by a screw 66 so that as the hand wheel 59 is in thebore 52 of the unit I6 to likewise cause similar motion in the rotatablesleeve 46 and the pin 4! may thus be adjusted lengthwise of the bar 36.A suitablegraduated collar 6I may be utilized in conjunction with thehand wheel 59' for accurate setting of the relative position of thebushing M and associated sleeve 46 and pin 41 to effect accurate andcareful adjustment of the depth of cut to be taken by the rifling toolas will now be described.

- Referring particularly to Figures II, V, and VI, to the end of thespiral grooved rifling bar 36 is appropriately fixed the rifling toolbar 62 by suitable coupling means 63 and to the outer end of this bar 62is appropriately fixed by suitable connecting means 64 the rifling toolhead comprising the main outer sleeve 65 which is thus positivelyconnected to the bar 62 and the spiral rifling grooved bar 36 so as tomove directly with it in both axial and rotary motion. Inside of thismain sleeve portion 65 is slidably mounted the tool feeding andrelieving member 66 which is slidably axially in the bore 61 of thesleeve 65. On a pivot pin 68, also referring to Figures VII, and VIII,is mounted the cutting tool member 69 which is arranged in a cut awayportion I0 formed in the member 66 and having each end portion II and I2which engage the taper actuating portions I3 and I4 respectively formedin the member 66. A suitable clearance slot I5 is formed in the member66 to permit relative sliding motion in the bore 61 of the member 65. Onthe tool holder 69 is formed the cutting bit I6 having a suitablecutting edge II arranged to operate upon the various rifle grooves 39 tobe formed in the bore 46 of the gun barrel.

It will be seen, particularly referring to Figure V, that relativesliding motion of the member 66 in the bore 61 of the sleeve 65 willcause the relative swinging motion of the cutting edge 11' of thecutting tool I6 in an arc of relative movement I8 the purpose of whichmovement is to effect the relief of the tool away from the work when itis being moved through the bore, to the i left in Figure V, for thebeginning of each cutting stroke and also to effect relative outwardadjustment of each return cutting position of the cutting edge 11relative to the bore of the gun so as to effect increasing depth of cutto finally complete the various grooves to be rifled. A significantdetail of construction of this particular tool holder lies in the factthat no resilient or spring mounted members of any kind are utilizedwhich would ordinarily result in chatter and lack 'of accurate controlparticularly in returning the tool away from the bore of the work duringthe tool relief motion at the end of each cut. This .is accomplished byproviding the rigid tool holder 69 with its integral tool I6. The toolholder is mounted on the pin 68 and has a firm nicetyvof engagementsimultaneously with the surfaces I3 and I4 on the member 66 at all timesso that as the member 66 is adjusted relative to the sleeve 65 the toolI6 will be in positive control both in its movement outwardly towardsthe work and return away from the work while at the same time providinga rigid, non-resilient structure for supporting the cutting tool I6.

This relative adjustment of the member 66 relative to the sleeve 65 iseffected automatically with each movement of the cutting tool in returnor feeding direction by means of the draw bar I9 which is appropriatelyconnected to the member 66 by suitable threaded connection 60 and whichprojects rearwardly through the rifling tool bar 62 and isconnectedpositively by suitabl'e thread connections 8| toa plunger '2slid'ably mount d in the bore 83' of the spiral rifiing groove bar 36,and arranged for aerial sliding therein. 'It will noted that the pin 41carried in the sleevefiii passes through this plunger '82 and istherefore positively connected thereto so as to definitely hold thisplunger 82 with respect to the sleeve 46 and therefore the 'feedadjustingunit 16. v 4

v It is therefore apparent that adjustment of the pilot hand wheel 59for relative movement of th'e sleeve 5! and therefore the sleeve '46will effect similar movement of the pin '41 and in the plunger '82 justdescribed in the bar 36 therefore causing relative movement of themember BB Xvith respect to the outer sleeve 61 and thereby effectingaccurate adjustment of the cutting end 1] of theto'ol Hi in the are 78to effect the proper depth of cut for each passage of thetool throughthe gunbo It will also be noted that automatic 5001 re] s efiected bythe relative reversal of direetidnjof the feeding cylinder l8 in movingthe carriage l5 and the feeding unit l6 to and from the barrel H. Forinstance, assuming the piston rod 11 to be moving to the right inFigures II, IV, and X, it 'will be noted that the collar 23 on thepiston rod 'I! will be pushing the carriage l5 to the right and thuscausing the bar t6 and thepbai 62 to be pulling the sleeve 65 throughthe "gun barrel. Under these conditions it will be notedthat the pin 47will be relatively to the right with res ed to the bar 36 so that theplunger 82 will like i have been moved relative to the right bar 36causing the surface 14 of the member 66, Figure V, to have been movedtoward the pin 68 and the tool holder 69 to bring the cutting edge T1 ofits toe] 16 up into cutting position as determined accurately to apredetermined amount by the setting of the pilot hand wheel 59 asdescribed. This is the condition prevailing at the time the sleeve 65 isbeing drawn through the gun b'ore toward the right in the variousfigures eiTecting the cutting action of the cutting edge 11 of the toolin each of the rifiing grooves. After the cutting edge and tool 16 havecome out of the right hand end of the gun sufiiciently to clear theirchips and cutting edge from the rifling groove therein, reversal of thecylinder I8 is then effected and the first motion taking place is thatof the movement of the unit IS without movement of the carriage l5 ascaused by the lost motion between the surface 3| of the carriage l5 andthe abutment collar on the piston rod I! as described. This lost motionor pre-movement of the feeding unit l6 relative to the carriage [5causes the pin 41 to again relatively move to the left with respect tothe in the arc 18 away from the bore of the gun barrel and as soon asthis has been accomplished the collar 25 on the piston rod I? will thenhave engaged the surface 3| of the carriage l5 to cause it to then bestarted in return rapid traverse movement thus moving the entire toolhead of Figure V back through the gun bore to the left hand end whilethe cutting tool is thus automatically retracted away from the variousrifling ooves.

After the rifling head has been moved surficiently far through the gunso that the cutting tool 76 then projects from the left hand end.

thereof the indexing head is then set in on by any conention a-l meanseither mutant or automatically by hydraulic me hanisn'i associsteawiththe ages-s set forth in the above 'copending a lication, to rotate theget to ew indexed st for repeater-lei the cu ti n i n each g grdcustbniary tice in such an arrangement is to move" the cu ting tool butto a definite depth "of cut re to the gm; bore and then t6 on to thesefeeding motions and complete indexing 6f the gun; around the full circlethus but each fining grows to a particular depth, then 1mg cam-plated acomplete 5 not git-eves a the pilot hand wheel-59 ii-nu fcircle or allof the rifiing grooves.

Another significant feature to be 15a: coma-r151 in conncun with theriding total 11 is the metrics or application of the coolant n forcooling the tool mm'remevm of chips the protection of this mechanismitem the c ps removed by the cutting tool. Coolant is supplied from theusual source through the flexible hose 84, Figure IV, and thus through asuitable con- 'duit to the bore 8'5 in the spiral grooved 'rifiing bar36 from which it passes misc the bore 8 3 and around the plunger 82 bymeans of the coolant passageways '87, best seen in Figure III, and thuscontinues into the chamber 88 and through the bore 89 surrounding thedraw rod 79 and thus through the passagewaysil into the bore 67 of thesleeve as. It is then passed through the coolant passageway 9| formed inthe sleeve 68 thus enterin'g into the cutaway portion ii] in which ismounted the tool 59. In this Way the coolant from this is brought intoposition to lubricate contact between the surfaces H and 13 and I2 and Has best seen in Figure V so as to prevent any foreign matterfrom'getting on the surfaces during the operation or the rifiing toolhead.- It will also be noted, particularly in Figure VI, that specialcoolant passageways 92 are provided each side of the cutting tool 76 tospecifically wash the chips away from the tool proper and away from thecutting edge T! and in the direction of travel of the broaching and therifling tool head to the gun bore so as to at all times keep chipsmoving away from the cutting tool, thus preventing damage and scoring ofthe work during the cutting operation.

It is also to be noted that suitable enclosure plates 93 and 94 suitablyfixed to the sleeve 65 by pins 95 and slidably mounted in appropriateguideways 9B and 91 in the member 66 forming tight sliding engagementwith the surfaces 98 and 99 formed as a true radius from the center ofthe pin 68 and nicely sliding against the end portions I00 and ID! ofthe respective plates 93 and 94 so as to form a completely enclosedchamber of the cut out portion 10 in the member 66 save for the exit ofcoolant fluid from the passageways 92, Figure VI. In this way a totallyenclosed mechanism is provided free of access of any foreign matter orchips while at the same time providing specific lubrication to thewearing contact surfaces between the tool holder 69 and the member 66and also providing specific exhausting of the coolant fluid from thechamber 10 at a point directly behind the cutting tool so as to wash thechips in the proper direction of motion of the rifiing tool head to thebore of the gun to prevent scoring of the work.

Having thus fully set forth and described this ie'ct another depth bfcut around the'coiiipl'ete invention what is claimed as new and desiredto secure by United States Letters Patent is:

1. In a gun rifling machine, a bed, means for rotatably mounting a gunbarrel longitudinally of said bed, means for indexing said gun to apredetermined series of rotary positions, a carriage slidably mounted onsaid bed longitudinally thereof, a tool feeding unit mounted on said bedbetween said carriage and said gun barrel and slidable longitudinallythereof, a fluid pressure cylinder mounted on said bed and having apiston rod directly connected to said tool feeding unit and connected tosaid carriage by a lost-motion arrangement, a rifling bar connected tosaid carriage and supported by said tool feeding unit, a rifling toolhead mounted on said bar for passing through the bore of said gun, andmeans for effecting feeding motion of the tool of said rifling head,radially of the axis of rotation of said gun band, by the relativemotion of said tool feeding unit and said carriage during the operationof said lost-motion mechanism.

2. In a rifling tool head for a gun rifiing machine, a sleeve slidablymounted in the bore of said gun, a tool holder pivotally mounted in saidsleeve, a cutting tool formed on said tool holder and having radialswinging motion relative to the axis of said gun bore, a member movablerelative to said sleeve and tool holder to eiTect said radial movementof the cutting edge of said 'tool, comprising a pair of opposedangularly reaxis of said gun bore, a member movable relative to saidsleeve and tool holder to efiect said radial movement of the cuttingedge of said tool, comprising a pair of opposed angularly relatedsurfaces each engaging the ends of said tool holder and each side of itspivotal mounting on said sleeve, so as to form firm contactingengagement at all times with said tool holder when said member is movedrelative to said sleeve, means for applying coolant inside of saidsleeve, and means for conducting coolant from inside of said sleevedirectly to said angularly related contact surfaces engaging said toolholder.

4. In a rifling tool head for a gun rifiing machine, a sleeve slidablymounted in the bore of said gun, a tool holder pivotally mounted in saidsleeve, a cutting tool formed on said tool holder and having radialswinging motion relative to the axis of said gun bore, a member movablerelative to said sleeve and tool holder to effect said radial movementof the cutting edge of said tool, comprising a pair of opposed angularlyrelated surfaces each engaging the ends of said tool holder and eachside of its pivotal mounting on said sleeve, so as to form firmcontacting engagement at all times with said tool holder when saidmember is moved relative to said sleeve, means for applying coolantinside of said sleeve, and means for conducting coolant from inside ofsaid sleeve directly to said angularly related contact surfaces engagingsaid tool holder, and means for conducting coolant from said membertoward the rearward portion of said cutting tool behind its cutting edgeand into engagement with the bore of said gun, and means for totallyenclosing said tool holder and said member in said sleeve to preventaccess of chips and foreign matter to the tool holder engaging surfacesof said member movable in said sleeve.

WILLIAM F. GROENE. HARRY F. STOFFREGEN, JR,

